Authors, T. G. Andronikashvili and G. V. Tsitsishvili, in Journal of Chromatography, 292, (1984), pages 3-8, show the use of synthetic zeolites of the X, Y and Z types, erionite and mordenite, as well as, natural zeolites, such as mordenite and clinoptilolite, for chromatographic separation of low-boiling inorganic and hydrocarbon gas mixtures. The zeolites referenced in the article were exchanged with Li.sup.+, K.sup.+, Rb.sup.+, Cs.sup.+, Ag.sup.+, Mg.sup.2+, Ca.sup.2+, Sr.sup.+, Ba.sup.2+ and Cd.sup.2+ and subsequently heated at 300.degree. C. to 500.degree. C. for four to several hours.
J. de Zeeuw and R. C. M. de Niss in Chrompack Topics, 12, (1985), pages 1-4, show the use of fused silica PLOT Molecular Sieve 5A for separating permanent gases.
T. A. Bretell and R. L. Grob in American Laboratory, October, 1985, pages 19-32, disclose the separation of permanent gases using long column and/or subambient temperatures. Column lengths varied from 15 to 33 feet, and temperatures from ambient to -78.degree. C. Two different materials were used for the separations, they are Molecular Sieve 5A and Chromosorb 102.
Another article by J. N. Gillis, R. E. Sievers and G. E. Pollock, Analytical Chemistry, 57, (1985), pages 1572 to 1577, teach the use of a metal chelate polymer column for separating argon and oxygen at ambient temperature from a 3 .mu.l sample of air. The limitations disclosed in the article are: it cannot perform argon/oxygen separations at temperatures above ambient, small sample volumes are used, high concentrations of components are separated with no mention of trace analysis and when oxygen is separated from the sample, argon and nitrogen coelute.
An article by G. E. Pollock, D. O'Hara and O. L. Hollis, in the Journal of Chromatographic Science, 22 (1984), pages 343-347, teaches the separation of permanent gases using divinyl-benzene, ethylene glycol dimethyacrylate and combinations of the two polymers. To obtain baseline resolution of the two components in the sample, especially argon and nitrogen, long columns, in excess of 30 feet, were used at subambient temperatures ranging from 2.degree. C. to 22.degree. C. In addition, high concentration samples were used for the analysis and no mention was made concerning sample volume.
Japanese Patent Application No. 59,233,203 teaches the use of various cation forms of mordenite for separating argon from gaseous mixtures containing nitrogen; no details are given concerning the activation procedure.
German Pat. No. 104,962 discloses a process for separating argon from gaseous mixtures containing nitrogen and/or oxygen using various forms of mordenite. The patent teaches that argon in dry air can be separated from nitrogen and oxygen over a sodium mordenite adsorbent, however, the nitrogen and the oxygen coelute unseparated.
Although the prior art has taught numerous systems for the separation of permanent gases, these systems have been unable to separate oxygen from argon at ambient conditions. The present invention achieves these separations, even at mild conditions.